1. Field of the Invention
This invention relates to packaging materials and specifically to packaging materials used for photographic elements. Still more specifically, this invention relates to packaging materials which are used with double-side coated X-ray photographic elements.
2. Background of the Invention
Photographic elements are light sensitive and must be packed for shipping with a great deal of care. This care is needed since the packaging must be light tight. Additionally, since the elements themselves are generally soft and subject to abrasion and the like, care must be taken to prevent damage during shipment. This damage (e.g., abrasion damage) is usually caused by individual sheets of film rubbing together within the packaging material.
Photographic X-ray elements require a high degree of packaging safety since any small mark or abrasion in the film may be mistaken during the X-ray evaluation of a patient, for example. X-ray film elements are usually finished in varying convenient sizes. These are usually sheets of sizes conventional in the medical X-ray industry such as 8 inches by 11 inches, or 10 by 14, among others. Sheets of these films are usually wrapped within a black, plastic bag (e.g., polyethylene) to prevent light leakage which might tend to expose the sensitive elements. This bag is usually placed within a conventional box made of some durable material such as cardboard. In order to prevent individual film sheets from movement within this box, it is usually conventional to include a stiffener on the top and on the bottom of the pack of film sheets prior to insertion within the bag. This stiffener is conventionally a sheet of cardboard of the approximate same size as the individual sheets of film which make up this package. At this point, after the bag which includes the stiffener sheets and the film sheets, is placed within the box, the entire package is sealed, labeled and is ready for shipment.
Photographic, X-ray elements conventionally are made by coating photosensitive emulsion (e.g., gelatino silver halide emulsions) on both sides of a support. An abrasion layer which usually comprises a gelatin layer containing hardeners or cross-linkers for the gelatin, is usually coated on top of each of the photosensitive layers mentioned above. Since this element is usually coated on a wide, long roll of the support (e.g., polyethylene terephthalate film), it must be chopped or finished to the requisite size before packaging. Hardening is still occurring during this step and sometimes the sheets of film have not reached the peak or optimum hardening stage prior to finishing and packaging. Thus, the photosensitive layer which will ultimately face the cardboard stiffener, for example, is still under-going this hardening step. These sheets of film tend to lose hardener which may be adsorbed by the cardboard sheet and thus the hardening of these particular elements is strongly affected by the presence of these stiffener sheets. There is, then, a pressing need to improve the stiffener elements used within the packaging systems of double-side coated X-ray film elements.